n6 



THE PROTEINS OF* THE WHEAT 



This globuliu is precipitated by saturating its solutions with magnesium 

 sulphate, but not with sodium chloride. Dissolved in 10 per cent sodium- 

 chloride solution, it is partly coagulated by boiling, but is not coagulated at 

 temperatures below 100. 



THE PROTEOSE. 



The wheat kernel yields a very small amount of proteose when extracted 

 with water. Whether this is an actual constituent of the seed or is formed 

 from the other proteins during its extraction and isolation was not definitely 

 ascertained. This proteose, like leucosin and globulin, is chiefly found in 

 the embryo. No preparations were made from the entire seed in sufficient 

 quantity to permit of analysis or examination of its properties. 



The proteose obtained from the embryo appeared to be a mixture of two 

 or more substances. A part was precipitated by saturating its solution with 

 sodium chloride ; a part was not. 



The analyses of these two parts showed the low percentage of carbon 

 characteristic of proteoses obtained by peptic digestion. Analyses of prepara- 

 tions thus obtained gave the following results : 



THE GLUTEN. 



The proteins of the wheat kernel differ from those that have been found 

 in any other seed by the fact that they may be largely separated as a coherent 

 elastic mass by washing the dough made from the flour under a gentle stream 

 of water. This protein mass has long been known as gluten. It consists 

 chiefly of gliadin and glutenin in combination with about twice their weight 

 of water, together with more or less starch, which can not be wholly removed 

 by washing, and also some fat, cholesterin, and lecithin. The non-protein 

 constituents usually form about 20 to 25 per cent of the crude gluten. The 

 protein constituents of the gluten, except for the fact that they are combined 

 with water, are present in the same form in the gluten as in the grain. 



